1. Field of the Invention
The present invention relates to a method for forming a photoelectric conversion device which converts light such as solar light into electric energy, and more particularly, it relates to a method for providing a photoelectric conversion device at good economy.
2. Prior Art
Photoelectric conversion devices using silicon semiconductors have shared the major part of the conventionally known devices, and those based on compound semiconductors such as gallium arsenide have also been put into practice for special uses. The photoelectric conversion devices using silicon semiconductors can be further classified into those using single crystal semiconductors, polycrystalline semiconductors, and amorphous semiconductors such as amorphous silicon. Those silicon based photoelectric conversion devices have each advantages and disadvantages depending on the application fields, and hence they are each used in the field at which their advantages can be fully exhibited.
A photoelectric conversion device based on single crystal semiconductors has a sufficiently high photoelectric conversion efficiency as to provide a large power output. Hence it is promising for use in power generation. However, the material cost and the like are still too high and cost reduction thereof is expected.
A photoelectric conversion device using a polycrystalline semiconductor can be fabricated at a lower material cost as compared with the device based on a single crystal semiconductor, however, it then suffers a lower photoelectric conversion efficiency. Accordingly, it has been desired to further reduce the cost to meet for the low conversion efficiency.
A photoelectric conversion device using an amorphous semiconductor has been developed initially with an aim to lower the fabrication cost of the device. However, no distinct merits with respect to the fabrication cost is found on the device. Moreover, the photoelectric conversion efficiency is as low as half or below. Hence, both the improvement of photoelectric conversion efficiency and the reduction of cost are required to the photoelectric conversion device of this type.
Furthermore, global conservation of resources and protection of environment are required extensively in the industrial field. Accordingly, more attention is paid to photoelectric conversion devices such as solar cells from the viewpoint of saving resources and environmental protection.
However, the solar cell, which is expected to be effective for conserving resources and for environmental protection problems, still consumes much resources due to problems such as low production yield and the use of excessive amount of materials.